The "oral history" part makes me think the "ledger" exists in the collective memory of a community. Plus, the value is purely defined on how hard the artifact was to get, not on any kind of intrinsic utility.

So not a million miles away from Gold then

Gold has some intrinsic utility. Even before electronics, it was useful as a visible display of wealth and power, which did have very tangible value.

And the whole malleability thing